I was going to respond there but decided to make a full post out of it and just link back to it here.
I’ve kitted out an incursion with basic stuff for now as I want to run missions to build up some capital. I know nothing about what skills I need next.
I think from an enjoyment point of view I want to be a trader or indeed a smuggler if you can be such a thing?
I want to buy and sell, but no idea what skills, ships or equipment I need for such a career.
So much to take in with this game.
As for what skills you need next, check the certificates of the Incursus (which is the ship I think you mean) and see what they reccomend. For early ships and skills the certificates are usually bang on. From my long-removed-from-beginner position I'd say concentrate on Small Hybrid weapons and associated gunnery skills to increase range, rate of fire, tracking, and damage. Also, for defence you want skills in the Mechanic area for armour plates, hardeners, energized plating, and repair systems, and finally skills from Navigation for speed, agility, and Afterburners.
I was a trader once. While there is not a specific career called "smuggler" there are several options for high stakes high rewards trading. In low sec, you can run NPC goods from sell order to buy order making healthy profit while trying to avoid gate camps and random pirates. I had some really good trade routes in the Placid Region doing this and only lost a ship once. Alternatively you can be bigger and do cross region trading of NPC trade goods or player modules/ships/ammo. Harder to find the good items as you need to see two markets at once but some people make vast fortunes doign this... but its not anywhere near smuggling.
Another option is 0.0 smuggling. Basically you buy modules/ammo/ships in cheap high sec hubs and transport them to dockable stations in null sec space. Its the biggest risk but also the highest rewards. Once I had space in a load going to fountain so I bought 200 Warp Core Stabilizers for 10K each and sold them for 200K each in Fountain region; you do the math. Another time I transported loads of large antimatter charges to Syndicate and sold at twice the price. Of course there is a reason for the profit margins: anyone and everyone will shoot at you so you run the risk of losing your shirt, but with the right ship and pilot experience it could be very lucrative.
The skills you need to be a good trader? Check out this webpage by Grismar, its old but the mechanics have not changed in that area at all since then and its very concise and clear.
One last thing: if simple market trading appeals to you, simply buying low and selling high in a market hub like Jita, Amarr, or Rens can net tidy profits with little effort, although you need a lot of input capital to make the big bucks.